An α-amylase sensitive bacteriocin of Leuconostoc carnosum

Abstract

Leuconostoc carnosum LA54A isolated from processed meat produces an antimicrobial substance that inhibits the growth of strains of lactic acid bacteria, Listeria monocytogenes and Enterococcus faecalis. The antibacterial substance was sensitive to proteases suggesting that Lc. carnosum is producing a bacteriocin. The bacteriocin was in addition sensitive against the activity of different α-amylases indicating that the molecule consists of a protein and a carbohydrate moiety. The bacteriocin was active over a wide pH range with an optimum between pH 3 and 5. It was stable after heat treatment at 100°C for 15 min. Optimum production of the bacteriocin by Lc. carnosum was during the late logarithmic phase. The purified bacteriocin showed a molecular weight of about 4000 Da when analyzed by SDS-polyacrylamide gel electrophoresis.